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TRANSACTIONS OF THE SECTIONS, 99 
palzeozoic times there was a coexistence of different centres of creation, analogous to 
those with which we are acquainted in the present day. Geological science ought 
therefore (as M. Barrande has well said) to lay due stress on this coexistence of 
different creatures, in comparing formations more or less typified by analogous faunas, 
but separated by notable geographical spaces. 
The simple form of the Silurian basin of Bohemia, the regularity, in a horizontal 
sense, of the concentric deposits of which it is composed, and the order of their 
superposition when viewed vertically, have enabled M. Barrande to recognise in the 
clearest manner, the order of succession of different partial faunas which characterize 
each of the stages of his basin. 
The fauna, which in Bohemia he names ‘ primordial’, is composed almost entirely 
of Trilobites (Paradowides, Conocephalus, Ellipsocephalus, Suv, &c.), an Orthis, and 
two species of Cystidee. The trilobites which then predominated are all distinguished 
by the common character of the great development of the thorax, as contrasted with 
-a very slender pygidium. This primordial fauna of Bohemia is represented, according 
to M. Barrande, in our country by the beds containing the Olenus in North Wales, 
and near the south-western extremity of the Malvern Hills, where those minute tri- 
lobites were discovered in lower Silurian rocks by Professor John Phillips. Now, 
the Olenus is found with species of Lingula in the lowest fossiliferous beds of Britain, 
associated with trappzan ashes and with the Paradowides, &c. Again, the same ge- 
nera, Olenus and Paradowides, reoccur in the lowest fossiliferous formations of Scan- 
dinavia, as well as in Britain and Bohemia. Thus, in the North of Europe, three 
countries, remote from each other, confirm the denomination of primordial given by 
M. Barrande, and sustain the published opinion of Sir Roderick Murchison, that the 
lower Silurian rocks contained the first created animals, which we can now recognize 
or describe*. 
The Silurian basin of Bohemia explored by M. Barrande during more than twelve 
years, and at a considerable expense, exhibits a richness of fossils of the older rocks 
hitherto quite unknown. That author estimates 1100 species at least; whilst the 
distinct forms now assembled in his own cabinet, and the following list, indicate the 
manner in which the different classes are represented. 
Crustaceans, nearly all Trilobites (about) ...,.....:.ssseee000 260 
Cephalopods .....,...0.ses00es ΡΥ eee ἫΝ sh eeddjpaskies,. 2348 
BECrapodsy casks cappissaadpangetsdanap Pee ee ee 1985 
Gasteropods .......+...++ ἬΕΙ λων δηλ μόραν sees 140 
Acephalous Mollusks ...... sass εάν cncdutat Sanaa d Gaby sp 140 
Brachiopods ........s+e+sese0s shaun ΜΕ ΡΝ 200 
Echinoderms, Zoophytes, &c. ... NFRD HE aes ἐν AOD 
Total fauna (about)...... 1105 
The state of preservation of these fossils, and the great number of specimens of each 
species collected by M. Barrande, have enabled him to throw much new light on the 
fauna of the most ancient (recognizable) inhabitants of our globe; and. thus zoology 
will not less profit than geology by his labours. 
_ At the preceding meeting of the British Association held at Birmingham, Sir 
Roderick Murchison communicated one of the facts the least expected in the natural. 
history of Trilobites. M. Barrande had then established the metamorphosis of three 
or four species of that family, and had sent one of the plates of his work in which 
were figured twenty distinct forms, all belonging to one species, the Sao hirsuta— 
from the embryo to the completion of the individual. A similar mode of transfor- 
mation has now been recognized by M. Barrande in nineteen forms of Bohemian 
trilobites, thus enabling the author to reduce considerably the number of supposed 
species. - 
* See chap. i. of Russia and the Ural Mountains, 1845, and Journ. Geol. Soc. Lond. 1845. 
_t See the commendation then bestowed on M. Barrande’s discoveries by the eminent 
naturalist M. Milne Edwards. Report of the Brit. Assoc. 1849, Transactions of the Sections, 
p- 59. 
Ὁ The fact of the metamorphosis of a British trilobite, the Oyygia Portlocki, has since 
been recognized by Mr. J. W. Salter. 
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